A few types of headlight cleaners or restorers are available. Most of which use harsh cleaners, cheap waxes and metal polish meant for other applications, and/or clear lacquer paint. The harsh cleaners, usually solvent based, can actually worsen or weaken the lens. Some have recommended the use of high speed buffers or rough sandpaper (around 400 grit) to remove tougher haziness. This can be very detrimental to the fragile plastic of the lens. Also this process is short lived and usually only lasts 1–2 months before it must be repeated. Sometimes the yellow haziness returns in less than 2 weeks. Some use clear lacquer paint to seal the lens. This paint is not meant for plastic and actually eats the plastic leaving a rough finish. It does not last long either as it has no protection against UV radiation and severe weather.
There are no known patents for headlight cleaners or restorers that remove yellowing or haziness.